Mal-assembly feature for explosive train fuzes

ABSTRACT

A safety device for an explosive train arming rotor type fuze comprising a dog co-acting with the arming rotor precluding malassembly of the fuze. The fuze may only be assembled when the rotor is properly held in its out-of-line safe position by the rotor release rod and the dog is therefore not obstructing the assembly of the outer housing.

United States Patent [191 Briggs et al.

MAL-ASSEMBLY FEATURE FOR EXPLOSIVE TRAIN FUZES Inventors: George S. Briggs, Adelphi, Md.;

Marvin W. Keith, Jr., Evanston, Ill.

The United States of America as represented by the Secretary of the Navy, Washington, DC.

Filed: Mar. 20, 1972 Appl. No.: 236,003

Assignee:

US. Cl. 102/76 R, 102/70 R Int. Cl. F42c 15/00 Field of Search 102/70, 76, 77, 78,

References Cited UNITED STATES PATENTS 7/1964 Sayles 102/79 Oct. 9, 1973 3,000,315 9/1961 Anastasia 102/78 X 3,117,522 l/l964 Hutchison et al.. 102/79 X 2,705,921 4/1955 Hoseman, Jr. 102/78 Primary Examiner-Samuel W. Engle Attorney-R. S. Sciascia et al.

[5 7] ABSTRACT A safety device for an explosive train arming rotors ,7

type fuze comprising a dog co-acting with the arming rotor precluding mal-assembly of the fuze. The fuze may only be assembled when the rotor is properly held in its out-of-line safe position by the rotor release rod and the dog is therefore not obstructing the assembly of the outer housing.

2 Claims, 3 Drawing Figures MAL-ASSEMBLY FEATURE FOR EXPLOSIVE TRAIN FUZES BACKGROUND OF THE INVENTION DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, wherein like refer- This invention relates generally to fuzes and more 5 ence numerals designate corresponding parts in the particularly to those of the explosive train, arming rotor type wherein an arming rotor containing a portion of the explosive train is held in an out-of-line safe position by a rotor release rod until it is desired to arm the device. In production of this type fuze, it has be possible to assemble the device with missing or defective parts, such as the rotor release rod, or with the arming rotor in the wrong position or the in-line position. This malassembly position is not obvious to personnel handling the projectile or bomb to which this fuze is attached, thus subjecting them to great danger and would permit the firing or dropping of the device in an armed and unsafe condition, also creating a great hazard. Furthermore, when the projectile or bomb reaches its intended target, the arming rotor likely would not be in the armed in-line position and hence, the device would be a dud.

Other attempts to solve the problem of occassional mal-assembly were too fragile and they are easily defeated by tampering, were of higher cost, had leakage problems, and may be ineffective because of the difficulty of interpretation and inaccessability of the indicator. Such indicating means were generally explosive train viewing windows or other visual indicators.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a fuze of the explosive train, arming rotor type having the feature of precluding mal-assembly.

Another object of the instant invention is to provide a fuze of the explosive train arming rotor type that may not be assembled in the armed position.

A further object of the invention is to provide a fuze of the explosive train arming rotor type not requiring visual indicators to show the proper out-of-line assembly of the arming rotor.

Briefly, these and other objects of the present invention are attained by the use of a free swinging lever or dog attached for rotation to the body of the fuze and co-acting with a spring rotated arming rotor. A groove in the arming rotor permits the mal-assembly dog to rotate inwardly permitting the outer housing of the fuze to be slid into place. If the groove in the arming rotor is not adjacent the mal-assembly dog, it will be held outwardly, precluding the outer housing to be slid into the final assembly position.

BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding of the invention and many of the attendant advantages thereof will be readily appreciated as the same become better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

FIG. 1 is a side viewin section and partially broken away showing the fuze in the proper assembled position;

FIG. 2 is a side view in section and partially broken away showing the armed position of the arming rotor; and,

FIG. 3 is a side view in section and partially broken away showing the mal-assembly position.

several views, there is shown in FIG. 1, FIG. 2, and FIG. 3 generally a fuze 10 having a fuze body 12. Within the fuze body 12 is mounted for rotation an arming rotor 14 rotatable by a helical spring about an axis perpendicular to the longitudinal dimension of the fuze I0. Arming rotor 14 has a transverse slot 16 for accepting a. rotor release rod 18 slidably contained within a bore 20 in the fuze body 12. Also contained within the arming rotor 14 is a transverse bore containing a portion of an explosive train 22 shown in the out-of-line position. Pivotally attached for freeswinging to the fuze body 12 by a pivot pin 24 is a mal-assembly dog 26 engaged in an annular slot or groove 28 made in the arming rotor 14. An outer housing 30 is shown in the position over the fuze body 12 and in contact with the mal-assembly dog 26 in FIG. 1.

As will now be evident from the several views of the drawing, FIG. 1 shows the fuze 10 completely assembled with the arming rotor 14 in the unarmed or safe position with the explosive train 22 out-of-line with the other portions 32 and 34 of the explosive train. The mal-assembly dog 26 is freely pivoted inwardly about the pivot pin 24 by the fact that the dog is in contact with the outer housing 30 and is forced into the annular slot 28 of the arming rotor 14. When the rotor release rod 18 is retracted out of the slot 16 of the arming rotor 14, the arming rotor 14 is free to rotate counterclockwise by the action of the spring with the malassembly dog 26 freely riding in the groove 28. The arming rotor 14 continues to rotate counter-clockwise until a cammed portion 29 of the groove 28 reaches the mal-assembly dog at which point it cams it against the inner surface of the outer housing 30, thus stopping the rotor in a position wherein the explosive train 22 is aligned in the total explosive train 32 and 34 as is shown in FIG. 2.

Referring now to FIG. 3 wherein the arming rotor 14 is shown in the mal-assembly position, it can be seen that the arming rotor 14 has rotated beyond the position, the explosive train 22 is no longer lined up vertically with the other portions 32 and 34 and the mal-assembly dog 26 is beyond the cammed portion 29 and resting on the outer periphery of the arming rotor. At this position, the dog obstructs the assembly of the outer housing 30. As is now evident, the mal-assembly dog 26 will preclude the assembly when the arming rotor 14 has been rotated by its spring to the malassembly position caused, for example, by the rotor release rod being absent at assembly. In fact, there can be no final assembly of the fuze in any position except the unarmed position as is shown in FIG. 1 because the arming rotor 14, if released by the absence of the rotor release rod or by other means, will continue to rotate counter-clockwise to the trial-assembly position as is shown in FIG. 3.

In the operation of the fuze in a projectile or a bomb, the normal sequence of events, among others, is to withdraw the rotor release rod 18 from the slot in the arming rotor 14 thereby permitting the arming rotor to rotate 90 counter-clockwise to position the portion of the explosive train 22 in vertical alignment between a primer above 32 and a booster below 34 below of which constitute other portions of the explosive train.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. An improvement in explosive train arming rotor type fuzes for ordnance precluding mal-assembly comprising:

a fuze body substantially cylindrical in shape;

a freely swingable dog pivotally attached to said fuze body for coacting with an arming rotor, having a first position inside and a second position outside the boundary of said fuze body;

an arming rotor mounted on an axis transversely of said fuze body, and spring biased for rotation;

an annular groove formed in a portion of the periphery of said arming rotor for receiving and co-acting with said freely swingable dog when in said first position; and

an outer housing surrounding said fuze body in close slidable relationship and interacting with said freely swingable dog to permit slidable assembly when in said first position, and to preclude assembly by said dog obstructing said outer housing when in said second position.

2. The device of claim 1 wherein:

said arming rotor has a transverse slot across the end thereof; and

a rotor release rod in said slot preventing rotation of said arming rotor until withdrawal of said rod. s 

1. An improvement in explosive train arming rotor type fuzes for ordnance precluding mal-assembly comprisIng: a fuze body substantially cylindrical in shape; a freely swingable dog pivotally attached to said fuze body for coacting with an arming rotor, having a first position inside and a second position outside the boundary of said fuze body; an arming rotor mounted on an axis transversely of said fuze body, and spring biased for rotation; an annular groove formed in a portion of the periphery of said arming rotor for receiving and co-acting with said freely swingable dog when in said first position; and an outer housing surrounding said fuze body in close slidable relationship and interacting with said freely swingable dog to permit slidable assembly when in said first position, and to preclude assembly by said dog obstructing said outer housing when in said second position.
 2. The device of claim 1 wherein: said arming rotor has a transverse slot across the end thereof; and a rotor release rod in said slot preventing rotation of said arming rotor until withdrawal of said rod. 